code: def testRegression(self):
      input = list(numpy.linspace(0.0, 1.0, 100)) + list(
          numpy.linspace(1.0, 0.0, 100)
      )
      self.assertAlmostEqualVector(
          DerivativeSFX()(input),
          [-0.0194097850471735, 0.010101020336151123],
      )
  
file_path: essentia/test/src/unittests/sfx/test_derivativesfx.py
imports: from essentia_test import *
  import numpy
label_desc: Use image node_id 6 for calling the TestDerivativeSfx obj's underlying member method code with example usage: obj.testRegression() without return types